下面的例子包含gbk，gb2312的<span style="COLOR: rgb(0,0,187)"><span style="FONT-FAMILY: Arial; COLOR: rgb(0,0,0)">例子：</span></span>
<span style="COLOR: rgb(0,0,187)"><?php <BR>$action </span><span style="COLOR: rgb(0,119,0)">= </span><span style="COLOR: rgb(0,0,187)">trim</span><span style="COLOR: rgb(0,119,0)">(</span><span style="COLOR: rgb(0,0,187)">$_GET</span><span style="COLOR: rgb(0,119,0)">[</span><span style="COLOR: rgb(221,0,0)">'action'</span><span style="COLOR: rgb(0,119,0)">]);<br>if(</span><span style="COLOR: rgb(0,0,187)">$action </span><span style="COLOR: rgb(0,119,0)">== </span><span style="COLOR: rgb(221,0,0)">"sub"</span><span style="COLOR: rgb(0,119,0)">)<br>{<br> </span><span style="COLOR: rgb(0,0,187)">$str </span><span style="COLOR: rgb(0,119,0)">= </span><span style="COLOR: rgb(0,0,187)">$_POST</span><span style="COLOR: rgb(0,119,0)">[</span><span style="COLOR: rgb(221,0,0)">'dir'</span><span style="COLOR: rgb(0,119,0)">]; <br> </span><span style="COLOR: rgb(255,128,0)">//if(!preg_match("/^[".chr(0xa1)."-".chr(0xff)."A-Za-z0-9_]+$/",$str)) //GB2312汉字字母数字下划线正则表达式 <br> </span><span style="COLOR: rgb(0,119,0)">if(!</span><span style="COLOR: rgb(0,0,187)">preg_match</span><span style="COLOR: rgb(0,119,0)">(</span><span style="COLOR: rgb(221,0,0)">"/^[\x{4e00}-\x{9fa5}A-Za-z0-9_]+$/u"</span><span style="COLOR: rgb(0,119,0)">,</span><span style="COLOR: rgb(0,0,187)">$str</span><span style="COLOR: rgb(0,119,0)">)) </span><span style="COLOR: rgb(255,128,0)">//UTF-8汉字字母数字下划线正则表达式<br> </span><span style="COLOR: rgb(0,119,0)">{ <br> echo </span><span style="COLOR: rgb(221,0,0)">"<font color="red">您输入的["</font></span><span style="COLOR: rgb(0,119,0)">.</span><span style="COLOR: rgb(0,0,187)">$str</span><span style="COLOR: rgb(0,119,0)">.</span><span style="COLOR: rgb(221,0,0)">"]含有违法字符"</span><span style="COLOR: rgb(0,119,0)">; <br> }<br> else <br> {<br> echo </span><span style="COLOR: rgb(221,0,0)">"<font color="green">您输入的["</font></span><span style="COLOR: rgb(0,119,0)">.</span><span style="COLOR: rgb(0,0,187)">$str</span><span style="COLOR: rgb(0,119,0)">.</span><span style="COLOR: rgb(221,0,0)">"]完全合法,通过!"</span><span style="COLOR: rgb(0,119,0)">; <br> }<br>}<br></span><span style="COLOR: rgb(0,0,187)">?><br></span><form method="POST" action="?action=sub">
<br>输入字符(数字,字母,汉字,下划线):<br> <input type="text" name="dir" value=""><br> <input type="submit" value="提交"><br>
</form>
